Suspension system for an aircraft turbine engine with dual-ball-joint and sliding pivot connection

Abstract

The invention relates to a suspension system for an aircraft turbine engine, which system comprises a set of connecting rods (25) each comprising connecting means (26, 27) for fastening the system between a casing (22, 23) of the turbine engine and an element of the aircraft. Each connecting rod (25) comprises, at one end, a ball-joint connection (26) and, at an opposite end, a ball-joint connection (27) and then a sliding pivot connection (28) provided with damping means (30, 31, 32).

Description

[0001] DESCRIPTION

[0002] TITLE: TURBOMACHINE SUSPENSION SYSTEM

[0003] D'AIRCRAFT WITH DOUBLE-BALL LINKAGE AND SLIDING PIVOT

[0004] technical field

[0005] The present invention relates to the field of turbomachinery used for aircraft propulsion and, more particularly, the attachment of a turbomachine to an aircraft component.

[0006] Previous techniques

[0007] As is known, a turbomachine is designed to provide the thrust necessary for the propulsion of an aircraft. It classically comprises, from upstream to downstream, considering the direction of an airflow admitted into the turbomachine, a fan allowing to accelerate the airflow admitted into the turbomachine and comprising blades generally extending in the same plane transverse to the axis of the turbomachine, at least one compressor, a combustion chamber and at least one turbine to drive the compressor in rotation.

[0008] Attaching an aircraft turbomachine to an aircraft component is carried out in the prior art by means of a suspension system comprising a clevis including load-bearing connecting rods fixed on one side to a turbomachine casing and on the other side to a hitch fixed to a pylon linked to the aircraft component.

[0009] An example of the realization of such a suspension system is illustrated in Figure 1, which shows an aircraft turbomachine, designated by the numerical reference 1, comprising a casing 2, for example an inter-compressor casing, which is suspended from a mounting pylon 3 by means of a set of straight or boomerang-shaped connecting rods 4 linked by ball joints, such as 5, to the casing 2, on the one hand and to a coupling 6 attached to the pylon 3, on the other hand.

[0010] According to another arrangement visible in figures 2 and 3, the turbomachine casing 2 is suspended by means of a set of centering rods 7 comprising a first end 8 connected by a ball joint to the turbomachine casing 2 and an opposite end 9 connected by a ball joint to a nacelle 10 linked to the mounting pylon 3.

[0011] In Figure 3, which corresponds to the implementation of Figure 2, the turbomachine's suspension system is attached to the exhaust casing or TRF (TRF being the acronym for "Turbine Rear Frame") of the turbomachine. The TRF casing comprises an inner ferrule 11 and an outer ferrule 12, the suspension system comprising centering rods 7 connected to the outer ferrule 12 and to the nacelle.

[0012] In aircraft turbomachinery, it is generally desirable to constrain transverse translations, i.e. perpendicular to the engine axis, and the rolling moment, coaxial with the engine of the turbomachine casing relative to the pylon.

[0013] State-of-the-art suspension systems are likely to generate undesirable stresses in the turbomachine casing, particularly under the action of the connecting rods, these stresses being likely to cause casing ovalization, eccentricity of load-bearings, or even localized punching of the casing.

[0014] Description of the invention

[0015] The aim of the invention is therefore to overcome these disadvantages and to propose a suspension system for aircraft turbomachinery which reduces stresses in the casing, in particular by allowing an additional degree of freedom.

[0016] The invention therefore has as its object a suspension system for an aircraft turbomachine, comprising a set of connecting rods each including means for attaching the system between a housing of the turbomachine and an element of the aircraft.

[0017] Each connecting rod includes at one end a ball joint and at the opposite end a ball joint and a sliding pivot joint.

[0018] Advantageously, the suspension system includes damping means.

[0019] For example, the damping means are fluid damping means. In one embodiment, the sliding pivot joint includes a stop to limit the sliding of the connecting rod.

[0020] The invention also relates to an aircraft turbomachine comprising a suspension system as defined above.

[0021] Brief description of the drawings

[0022] Other objects, features and advantages of the invention will become apparent from the following description, given solely by way of non-limiting example, and made with reference to the accompanying drawings in which:

[0023] Figures [Fig 1], [Fig 2] and [Fig 3], which have already been mentioned, schematically illustrate a turbomachine equipped with a suspension system according to the state of the art;

[0024] Figure 4 schematically illustrates a turbomachine equipped with a suspension system according to the invention;

[0025] Figure 5 illustrates an example of the implementation of the stop suspension system;

[0026] Figure 6 illustrates an example of an embodiment of the suspension system including damping means; and

[0027] Figure 7 illustrates an example of the implementation of damping means integrated into the suspension system.

[0028] Detailed description of at least one embodiment

[0029] Reference will be made to Figure 4, which illustrates a turbomachine 20 equipped with a suspension system 21 according to the invention.

[0030] The invention relates essentially to the suspension system, only the part of the turbomachine 20 to which the suspension system is attached has been illustrated in figure 4.

[0031] A turbomachine extends along a turbomachine axis X and allows an aircraft to be propelled from an airflow entering the turbomachine and circulating from upstream to downstream, the terms upstream and downstream being defined with respect to the turbomachine axis X, considering the direction of the airflow in the turbomachine.

[0032] As is known, the turbomachine comprises, from upstream to downstream, a blower and a gas generator including a low pressure compressor, a high pressure compressor, a combustion chamber, a high pressure turbine and a low pressure turbine.

[0033] The low-pressure compressor, together with the low-pressure turbine to which it is connected by a turbine shaft, forms a low-pressure (LP) unit that drives the blower in rotation. The high-pressure compressor, together with the high-pressure turbine to which it is connected by a shaft, forms a high-pressure (HP) unit.

[0034] The fixed structural components of the turbomachine include, in particular, an inlet casing located at the inlet of the gas generator, an inter-compressor casing, located between the low-pressure compressor and the high-pressure compressor, and a TRF exhaust casing directly at the outlet of the low-pressure turbine.

[0035] The turbomachine is supported by a suspension system 21 attached to the turbomachine casing, in particular to the TRF casing comprising an inner ferrule 22 and an outer ferrule 23, and to the nacelle 24 attached to an element of the aircraft, for example under a wing.

[0036] The suspension system consists of a set of centering rods, such as 25, arranged between the turbomachine and the aircraft element, in particular between the TRF casing of the turbomachine and the nacelle and regularly spaced around the turbomachine.

[0037] The nacelle 24 is a structural nacelle, in that it allows centering of the turbomachine housing by means of the centering rods 25.

[0038] The centering rods include, at their mutually opposite ends, means for connecting to the TRF housing and the nacelle, respectively. The connecting means include ball joints 26, 27 and a sliding pivot joint 28.

[0039] As illustrated in Figure 4, each connecting rod includes at one end a ball joint 26, by which it is fixed to the outer ferrule of the housing, and at its opposite end a ball joint 27 associated with a sliding pivot joint 28.

[0040] The upstream end of the connecting rod is provided with a ball joint 26. The opposite downstream end is provided with a ball joint 27 and then a sliding pivot joint. The axis of the sliding pivot joint is parallel to the X-axis of the turbomachine.

[0041] Compared to a two-ball joint connection, in which the forces applied along the axis of the connecting rod are referred to the housing and to the aircraft element to which the suspension system is attached, a double-ball joint connection associated with a sliding pivot connection makes it possible to avoid the blocking of uniform expansions of the centering rods or differential expansions between the connecting rods, each connecting rod being free to move along the sliding pivot connection, in the axis of the connection, when the engine and the connecting rods expand thermally.

[0042] However, the axial-radial translations of the downstream end of the connecting rod are not restricted. The degrees of freedom of each connecting rod make the suspension system robust and reliable in the event of different axial and radial expansions, during engine heating or cooling.

[0043] The suspension system, which includes a double ball joint coupled with a sliding pivot joint, allows radial movement of the housing, which implies less radial stress compared to a double ball joint system.

[0044] Referring to figures 5 and 6, it is therefore advantageous, in one embodiment, for the suspension system to be equipped with suspension means comprising a double ball joint 26, 27 coupled to a sliding pivot link 28 with stop or with shock absorber.

[0045] In the embodiment of figure 5, the sliding pivot joint 28 is provided with a stop 29.

[0046] Such a stop prevents the sliding pivot from moving vertically along the connecting rod of the housing, thus preventing the housing from moving radially. This ensures that operating or misalignment loads are fully absorbed.

[0047] In the embodiment of figure 6, the sliding pivot joint is provided with damping means.

[0048] These damping means are, for example, fluid-filled damping means, such as oil-filled damping means, capable of filtering high-frequency loads and thus allowing the sliding pivot to absorb the loads generated during aircraft maneuvers. For example, the damping means comprise a cylinder 30 filled with oil or a suitable fluid, for example, connected to the nacelle and comprising two communicating chambers between which a calibrated passage 31 is provided, and a plunger piston 32 connected, for example, to a connecting rod, with a return spring 33 associated with the piston. The partition 34 separating the two chambers of the cylinder 30 can advantageously act as a stop for the piston.

[0049] It should be noted that the invention which has just been described, which uses connecting means comprising a ball joint 26 and a sliding pivot joint 27, applies to any suspension system comprising any number of centering rods.

[0050] Furthermore, the invention is not limited to a suspension system used for centering a TRF housing but also applies to other attachment points located on the turbomachine housing.

Claims

DEMANDS 1. Suspension system for aircraft turbomachine, comprising a set of connecting rods (25) each comprising connecting means (26, 27) for fixing the system between a housing (22, 23) of the turbomachine and an element of the aircraft, characterized in that each connecting rod (25) comprises at an upstream end with respect to a turbomachine axis (X) a ball joint (26) by which the connecting rod (25) is fixed to the housing of the turbomachine and at an opposite downstream end a ball joint (27) and then a sliding pivot joint (28) provided with damping means (30, 31, 32).

2. Suspension system according to claim 1, wherein the damping means are fluid damping means.

3. Suspension system according to any one of claims 1 to 2, wherein the sliding pivot joint includes a stop (29) for limiting the sliding of the connecting rod.

4. Aircraft turbomachine comprising a suspension system according to any one of claims 1 to 3.

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